Not Applicable
Not Applicable
1. Field of the Invention
This invention relates to cardio myopathy and the treatment thereof.
2. Description of the Prior Art
By way of background, cardio myopathy, as caused for example by myocardial infarction, is a common disorder. Twenty thousand new cases are reported yearly in the United States and 25-50% of such cases will result in death after three years. The problem is that damaged adult heart muscle does not regenerate and myocardial functionality cannot be restored using the body""s natural healing mechanisms. The myocardium tends to dilate and areas of the ventricular walls may become hypokinetic, or even akinetic, such that congestive heart failure often develops in affected individuals.
Previous medical techniques have not substantially reduced the morbidity or mortality of this condition. Past efforts in this area include removing autologous muscle cells, stem cells, etc., and culturing them to generate the large number of implantation cells necessary for myocardial repair. The cultured cells are then implanted via injection into the myocardium, where they have an opportunity to regenerate new heart muscle. Applicant has previously proposed a cell patch method whereby autologous muscle grafts are applied to damaged myocardial tissue. See U.S. Pat. No. 5,327,913. According to this method, the muscle grafts are placed against a patient""s outer myocardial wall and a section of the patient""s greater omentum is applied over the grafts to supply blood to the transplanted tissue. In a recently developed improvement of the cell patch method, a percutaneous procedure is used to secure the muscle grafts to the myocardium. Applicant has also recently proposed a micro-granule treatment wherein autologous myocyte micro-granules are injected into a patient""s inner or outer myocardial wall using an injection needle introduced via a transfemoral or surgical approach.
Evaluation of these previous treatment proposals suggests a need for a more efficient method of applying myocyte donor material to the myocardium. For example, a cell patch method that did not require the suturing of muscle grafts would greatly simplify and expedite a cell patch procedure. Similarly, a cultured cell or micro-granule injection treatment that did not require repeated individual injections would greatly improve the implementation of such procedures. A new apparatus and method for myocardial repair and treatment is therefore indicated.
The foregoing problems are solved and an advance in the art is obtained by a novel cradle apparatus for autologous myocardial repair and treatment. The cradle apparatus includes a cradle having a base end and an open end, and is adapted to apply a myocardial repair or treatment material to a dysfunctional myocardium. A lumen extends to a location which is at or near a base end of the cradle. In two disclosed embodiments of the cradle, a plurality of spring arms are mounted to the lumen and also attach to the open end of the cradle. The spring arms are biased to apply an opening force to the open end of the cradle, whereby the cradle apparatus can be compacted into a percutaneous or transarterial introducer and then expanded upon emergence from the introducer to engage a ventricular wall of a heart. In particular, the cradle apparatus can be adapted to be twisted and compacted inside the introducer, which will typically be generally tubular in shape.
The spring arms can be made from metal and the lumen is adapted to receive one or more instruments, including a suction cup mounted to a hydraulic sheath that extends through the lumen. This instrument is used to elevate the apex of a heart to receive the cradle apparatus.
In accordance with a first one of the foregoing embodiments, the cradle is configured as a prosthesis for holding a material against a myocardium. In that case, the cradle includes a constrictor at its open end and is removably attached to the spring arms. According to a second one of the foregoing embodiments, the cradle is configured for applying a material into or on a myocardium via a pericardial approach. In that case, the cradle includes a double-walled inflatable bladder having a system of needles on one wall thereof adapted to dispense the material.
A third embodiment is also disclosed wherein the cradle apparatus does not utilize spring arms. In this embodiment, the cradle is configured for applying a material into or on a myocardium (or a coronary arterial wall) via an endocardial approach. The cradle includes an inflatable balloon having a system of needles adapted to dispense the material.
A combination of the cradle configurations may likewise be employed in accordance with the invention. For example, the cradle apparatus may include first and second cradles. The first cradle is configured for applying a material into or on a myocardium via a pericardial approach, and includes a double-walled inflatable bladder having a system of needles on one wall thereof adapted to dispense the material. The second cradle is configured for applying a material into or on a myocardium (or coronary arterial wall) via an endocardial approach, and includes an inflatable balloon having a system of needles adapted to dispense the material.